FLORA OF VIETNAM Polypodiaceae s.l. Asplenium sp. ("creeping")
N.Vietnam, Bac Kan Prov., Cho Don Distr., Ban Thi Municipality, village Phia Khao, around point 22°15′52′'N, 105°32′01′'E at elevation 800-900 m a.s.l. (Po Luong mountain).
Primary broad-leaved evergreen closed forest on very steep slopes and cliffs near and on tops of rocky ridge composed with solid marble-like stratified limestone.
Lithophytic and epiphytic fern in shady place. Very common.